Fixed the logic that prevents all cluster slot requests sent to speci…

…fic instances (#1928)

* Fixed the logic that prevents all cluster slot requests sent to specific instances when jedis is initialized on many processes(such as storm with a lot of works), It can cause high CPU and the impact of many slow queries.

* Replace each tab with two spaces.

* merge

* reduce one possible import

Co-authored-by: wenjian.wu <wenjian.wu@vipshop.com>
Co-authored-by: dengliming <liming.d.pro@gmail.com>
Co-authored-by: M Sazzadul Hoque <7600764+sazzad16@users.noreply.github.com>

src/main/java/redis/clients/jedis/JedisClusterConnectionHandler.java

@@ -1,6 +1,8 @@
 package redis.clients.jedis;
 
 import java.io.Closeable;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Map;
 import java.util.Set;
 import javax.net.ssl.HostnameVerifier;
@@ -117,8 +119,10 @@ public Map<String, JedisPool> getNodes() {
   }
 
   private void initializeSlotsCache(Set<HostAndPort> startNodes, JedisClientConfig clientConfig) {
+    ArrayList<HostAndPort> startNodeList = new ArrayList<>(startNodes);
+    Collections.shuffle(startNodeList);
 
-    for (HostAndPort hostAndPort : startNodes) {
+    for (HostAndPort hostAndPort : startNodeList) {
       try (Jedis jedis = new Jedis(hostAndPort, clientConfig)) {
         cache.discoverClusterNodesAndSlots(jedis);
         return;